Regex to validate passwords with characters restrictions

Question

I need to validate a password with these rules:

• 6 to 20 characters
• Must contain at least one digit;
• Must contain at least one letter (case in

Answer 1

Regex could be:-

^(?=.*\d)(?=.*[a-zA-Z])[a-zA-Z0-9!@#$%&*]{6,20}$

How about this in Javascript:-

function checkPwd(str) {
    if (str.length < 6) {
        return("too_short");
    } else if (str.length > 20) {
        return("too_long");
    } else if (str.search(/\d/) == -1) {
        return("no_num");
    } else if (str.search(/[a-zA-Z]/) == -1) {
        return("no_letter");
    } else if (str.search(/[^a-zA-Z0-9\!\@\#\$\%\^\&\*\(\)\_\+]/) != -1) {
        return("bad_char");
    }
    return("ok");
}

Also check out this